1. Field of the Invention
Example embodiments of the invention relate to a photovoltaic power generation system.
2. Description of the Related Art
Recently, as existing energy sources such as petroleum and coal are expected to be depleted, interests in renewable energy sources for replacing the existing energy sources are increasing. Among the renewable energy sources, solar cells for generating electric energy from solar energy have been particularly spotlighted.
A solar cell generally includes a substrate and an emitter layer, each of which is formed of a semiconductor, and electrodes respectively formed on the substrate and the emitter layer. The semiconductors forming the substrate and the emitter layer have different conductive types, such as a p-type and an n-type. A p-n junction is formed at an interface between the substrate and the emitter layer.
When light is incident on the solar cell, a plurality of electron-hole pairs are generated in the semiconductors. The electron-hole pairs are separated into electrons and holes by the photovoltaic effect. Thus, the separated electrons move to the n-type semiconductor (e.g., the emitter layer) and the separated holes move to the p-type semiconductor (e.g., the substrate), and then the electrons and holes are collected by the electrodes electrically connected to the emitter layer and the substrate, respectively. The electrodes are connected to each other using electric wires to thereby obtain electric power.
The solar cell may be individually used, or the plurality of solar cells having the same structure may be connected in series or in parallel to one another to manufacture a solar cell module for efficient use and easy installation. Accordingly, a desired number of solar cell modules may be connected to one another to manufacture a module array, i.e., a solar cell panel. A user may obtain electric power from the solar cell panel.